GNU gettext PO (Portable Object)¶

Most widely used format for translating libre software.

Contextual info stored in the file is supported by adjusting its headers or linking to corresponding source files.

Showing source string change¶

Weblate can extract previous source strings from the PO files if present and show the string difference for strings needing editing based on that. To include these, msgmerge has to be executed with --previous and the resulting PO file then contains lines such as:

#, fuzzy
#| msgid "previous-untranslated-string"
msgid "untranslated-string"
msgstr "translated-string"

This is controlled by the po_keep_previous File format parameters parameter. It does not affect obsolete entries marked with #~.

Obsolete strings¶

msgmerge keeps strings removed from the POT file as obsolete #~ entries by default. Enable the po_remove_obsolete File format parameters parameter to remove obsolete entries when Weblate saves PO files.

PO file header¶

The header of the PO file is automatically maintained by Weblate. It can be configured to include the Language-Team, Last-Translator, X-Generator and Report-Msgid-Bugs-To headers using the File format parameters.

Contributor comments¶

Use the po_contributor_comments File format parameters parameter to add contributor names and years to PO header comments. Choose gettext for traditional comments or spdx for SPDX copyright entries. The default, none, disables contributor updates without removing existing comments. This setting works independently of the Last-Translator header setting.

With gettext, contributor comments look like this:

# Jane Doe <jane@example.com>, 2024, 2026.

With spdx, the same entry becomes:

# SPDX-FileCopyrightText: 2024, 2026 Jane Doe <jane@example.com>

On the next commit by an eligible contributor, SPDX mode converts all recognized contributor comments, preserves historical contribution years, and adds the current year for that contributor. Anonymous Weblate authors are skipped. Unrelated comments and copyright notices are preserved. Weblate does not infer copyright claims from translated credit strings or add project-specific notices or license identifiers; handle these in custom tooling.

Line wrapping¶

The line wrapping mostly matches GNU gettext behavior. Both the wrapping algorithm in the GNU gettext and the Unicode data the wrapping is based on evolve which might cause differences in some corner cases.

The wrapping width can be configured using the po_line_wrap parameter, see File format parameters.

Generating matching MO files¶

In case MO files are kept in the repository together with PO files, Generate MO files can be used to keep them up-to-date with PO files.

Updating PO files from the POT file¶

Update PO files to match POT (msgmerge) can be used to update PO files from the POT file, see Updating target-language files.

Monolingual gettext¶

Some projects decide to use gettext as monolingual formats—they code just the IDs in their source code and the string then needs to be translated to all languages, including English. This is supported, though you have to choose this file format explicitly when importing components into Weblate.

Example files¶

The bilingual gettext PO file typically looks like this:

#: weblate/media/js/bootstrap-datepicker.js:1421
msgid "Monday"
msgstr "Pondělí"

#: weblate/media/js/bootstrap-datepicker.js:1421
msgid "Tuesday"
msgstr "Úterý"

#: weblate/accounts/avatar.py:163
msgctxt "No known user"
msgid "None"
msgstr "Žádný"

The monolingual gettext PO file typically looks like this:

#: weblate/media/js/bootstrap-datepicker.js:1421
msgid "day-monday"
msgstr "Pondělí"

#: weblate/media/js/bootstrap-datepicker.js:1421
msgid "day-tuesday"
msgstr "Úterý"

#: weblate/accounts/avatar.py:163
msgid "none-user"
msgstr "Žádný"

While the base language file will be:

#: weblate/media/js/bootstrap-datepicker.js:1421
msgid "day-monday"
msgstr "Monday"

#: weblate/media/js/bootstrap-datepicker.js:1421
msgid "day-tuesday"
msgstr "Tuesday"

#: weblate/accounts/avatar.py:163
msgid "none-user"
msgstr "None"

Supported features¶
File extensions	`.po`, `.pot`
Linguality ⓘ	Monolingual
Supports plural ⓘ	`Yes`
Supports descriptions ⓘ	`Yes`
Supports explanation ⓘ	`No`
Supports context ⓘ	`Yes`
Supports location ⓘ	`Yes`
Supports flags ⓘ	`Yes`
Additional states ⓘ	`Needs editing`
API identifier	`po-mono`
Supports read-only strings ⓘ	`No`
Supports removing obsolete strings ⓘ	`Yes`

Supported features¶
File extensions	`.po`, `.pot`
Linguality ⓘ	Bilingual
Supports plural ⓘ	`Yes`
Supports descriptions ⓘ	`Yes`
Supports explanation ⓘ	`No`
Supports context ⓘ	`Yes`
Supports location ⓘ	`Yes`
Supports flags ⓘ	`Yes`
Additional states ⓘ	`Needs editing`
API identifier	`po`
Supports read-only strings ⓘ	`No`
Supports removing obsolete strings ⓘ	`Yes`

Weblate configuration¶

Typical Weblate Component configuration for bilingual gettext
File mask	`po/*.po`
Monolingual base language file	Empty
Template for new translations	`po/messages.pot`
File format	Gettext PO file

Typical Weblate Component configuration for monolingual gettext
File mask	`po/*.po`
Monolingual base language file	`po/en.po`
Template for new translations	`po/messages.pot`
File format	Gettext PO file (monolingual)

File format parameters¶

File format parameters with the pattern po_* can be used to configure the behavior of the gettext format.